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Related papers: Magnus expansion for a chirped quantum two-level s…

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We build an efficient and unitary (hence stable) method for the solution of the semi-classical Schr\"odinger equation subject with explicitly time-dependent potentials. The method is based on a combination of the Zassenhaus decomposition…

Numerical Analysis · Mathematics 2016-02-12 Philipp Bader , Arieh Iserles , Karolina Kropielnicka , Pranav Singh

We investigate how dynamical decoupling methods may be used to manipulate the time evolution of quantum many-body systems. These methods consist of sequences of external control operations designed to induce a desired dynamics. The systems…

Quantum Physics · Physics 2015-05-18 Julie Dinerman , Lea F. Santos

A general method is introduced for verifying multitime quantum correlations through the characteristic function of the time-dependent P functional that generalizes the Glauber-Sudarshan P function. Quantum correlation criteria are derived…

Quantum Physics · Physics 2016-06-30 F. Krumm , J. Sperling , W. Vogel

The solution of a two level system driven by a Laser in the adiabatic limit is determined using third order Magnus expansion. We made the assumption that the laser is on resonance or close to resonance with the Bohr transition. As a…

Quantum Physics · Physics 2016-10-20 Dawit Hiluf Hailu

We study the full time evolution of one- and two-mode bosonic quantum systems that interact through single- and two-mode squeezing Hamiltonians. We establish that the single- and two-mode cases are formally equivalent, leading to the same…

Quantum Physics · Physics 2018-05-21 Chester Moore , David Edward Bruschi

The dynamics of the spin-boson Hamiltonian is considered in the stochastic approximation. The Hamiltonian describes a two-level system coupled to an environment and is widely used in physics, chemistry and the theory of quantum measurement.…

Quantum Physics · Physics 2016-09-08 L. Accardi , S. V. Kozyrev , I. V. Volovich

The long-term evolution of astrophysical systems is driven by a Hamiltonian that is independent of the fast angle. As this Hamiltonian may contain explicitly time-dependent parameters, the conservation of mechanical energy is not guaranteed…

Earth and Planetary Astrophysics · Physics 2024-05-29 Barnabás Deme

We examine several numerical techniques for the calculation of the dynamics of quantum systems. In particular, we single out an iterative method which is based on expanding the time evolution operator into a finite series of Chebyshev…

Strongly Correlated Electrons · Physics 2015-05-13 Holger Fehske , Jens Schleede , Gerald Schubert , Gerhard Wellein , Vladimir S. Filinov , Alan R. Bishop

We construct a Hamiltonian whose dynamics simulate the dynamics of every other Hamiltonian up to exponentially long times in the system size. The Hamiltonian is time-independent, local, one-dimensional, and translation invariant. As a…

Quantum Physics · Physics 2017-10-26 Thomas C. Bohdanowicz , Fernando G. S. L. Brandão

Discrete and continuous variables oftentimes require different treatments in many learning tasks. Identifying the Hamiltonian governing the evolution of a quantum system is a fundamental task in quantum learning theory. While previous works…

Quantum Physics · Physics 2025-06-03 Tim Möbus , Andreas Bluhm , Tuvia Gefen , Yu Tong , Albert H. Werner , Cambyse Rouzé

In this paper, time-dependent dynamical systems given by sequences of maps are studied. For systems built from expanding C^2-maps on a compact Riemannian manifold M with uniform bounds on expansion factors and derivatives, we provide…

Dynamical Systems · Mathematics 2015-06-23 Christoph Kawan

We study the time evolution of an ideal system composed of two harmonic oscillators coupled through a quadratic Hamiltonian with arbitrary interaction strength. We solve its dynamics analytically by employing tools from symplectic geometry.…

Considering a two-level quantum system, we have proposed and represented a new approach for robust population transfer. In this scheme, the laser frequency has been swept in a finite time interval which simplifies the experimental…

Atomic Physics · Physics 2018-10-11 Fatemeh Ahmadi Nouri , Mehdi Hosseini , Farrokh Sarreshtedari

A simple derivation of the effective spin-wave Hamiltonian for a double-exchange system with infinitely large Hund's-rule coupling is demonstrated. The formalism can be applied to models with arbitrary range of hopping as well as those with…

Strongly Correlated Electrons · Physics 2007-05-23 Nobuo Furukawa , Yukitoshi Motome

We propose an algorithm for simulating the dynamics of a geometrically local Hamiltonian $A$ under a small geometrically local perturbation $\alpha B$. In certain regimes, the algorithm achieves the optimal scaling and outperforms the…

Quantum Physics · Physics 2024-04-05 Kunal Sharma , Minh C. Tran

We derive a Markovian master equation that models the evolution of systems subject to driving and control fields. Our approach combines time rescaling and weak-coupling limits for the system-environment interaction with a secular…

Quantum Physics · Physics 2024-11-26 Giovanni Di Meglio , Martin B. Plenio , Susana F. Huelga

The study of phase transitions in dissipative quantum systems based on the Liouvillian is often hindered by the difficulty of constructing a time-local master equation when the system-environment coupling is strong. To address this issue,…

Quantum Physics · Physics 2024-04-09 H. T. Cui , Y. A. Yan , M. Qin , X. X. Yi

Quantum optimal control theory is becoming increasingly crucial as quantum devices become more precise, but the need to quickly optimize these systems classically remains a significant bottleneck in their operation. Here we present a new…

Quantum Physics · Physics 2022-05-11 Mogens Dalgaard , Felix Motzoi

The issue of separating Schr\"odinger-type quantum time evolution into a product of holonomic and dynamical parts in the non-adiabatic non-Abelian case is examined. We identify all special cases in which this kind of separation is possible,…

Quantum Physics · Physics 2026-02-24 Adam Fredriksson , Erik Sjöqvist

We propose a new variational quantum algorithm, which we refer to as TIMES-ADAPT, that prepares time-evolved states in a low-energy or symmetric subspace of a time-independent Hamiltonian on a quantum computer. Using a specially trained…